Maven build fails with "package com.fasterxml.jackson does not exist"-CodePudding

I need to parse a json file in my maven project. For that I started with a simple import in my java file (App.java)

package com.mycompany.app;
import com.fasterxml.jackson.*;// <-------- HERE
public class App
{
    public static void main( String[] args )
    {
    }
}

Then, I tried to compile the project by using mvn package but I got an error:

[INFO] Scanning for projects...
[INFO] 
[INFO] ----------------------< com.mycompany.app:my-app >----------------------
[INFO] Building my-app 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] 
[INFO] --- maven-resources-plugin:3.0.2:resources (default-resources) @ my-app ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] skip non existing resourceDirectory /tmp/my-app/src/main/resources
[INFO] 
[INFO] --- maven-compiler-plugin:3.8.0:compile (default-compile) @ my-app ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 1 source file to /tmp/my-app/target/classes
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /tmp/my-app/src/main/java/com/mycompany/app/App.java:[2,1] package com.fasterxml.jackson does not exist
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.628 s
[INFO] Finished at: 2022-05-10T15:31:39 02:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.0:compile (default-compile) on project my-app: Compilation failure
[ERROR] /tmp/my-app/src/main/java/com/mycompany/app/App.java:[2,1] package com.fasterxml.jackson does not exist
[ERROR] 
[ERROR] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

Here is how I built my maven project:

I created my maven project:

mvn -B archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.4

I modified the file App.java (created by the previous command) to match with my file.
I modified pom.xml in order to add the dependency:

<!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-core</artifactId>
    <version>2.13.2</version>
</dependency>

Do you know how to solve this error?

CodePudding user response：

I've already recently answered a similar question: the problem is that com.fasterxml.jackson is not a package, there is a folder com/fasterxml/jackson (see the source), but not a package. In Java, package is a namespace that contains at least one class. Asterix import imports non-recursively all the classes in the package. So, if you need, let's say, to use classes JsonParser.java and JacksonException.java from the package com.fasterxml.jackson.core, you may add an asterix import like that: com.fasterxml.jackson.core.*